Such inductive torque sensor devices are generally considered known. They are, for example, being used in motor vehicles in order to determine torque values, such as steering torque. Such measures are becoming increasingly necessary, due to the fact that electromotive servos are being used as steering aids in more and more vehicles. These require the steering torque input for control purposes. The steering torques are determined by a torsion bar inside the steering column using angular differences and calculated from this information. To this end, twists at the end of the torsion bar are converted to electronic signals using a suitable arrangement and fed into other devices for evaluation purposes. The angular differences caused by torsion are to be determined independently of the position of the steering wheel.
It is additionally important for driver assistance systems, such as ESP (electronic stability program used to influence the driving behavior of the vehicle), to receive information as to the positioning of the steering wheel (relative angular position). For this purpose, the lock of the steering wheel (angle relative to a reference position) is determined. To allow for angles greater or less than 360° to be determined, the reference position is associated with an indexing system, which generates a signal for every full revolution of the steering wheel and thereby determines the number of revolutions performed by the steering wheel.
EP 1 533 212 B1 describes a steering angle sensor where a rotor is directly mounted on a circuit board. For this purpose, a bearing element is latched onto the circuit plate. A rotor structure is mounted on a counter-bearing ring which is rotatably mounted inside the bearing element. This is supposed to achieve an exact positioning of the rotor structure in relation to the circuit board. The effects of temperature and wear cannot be compensated for.
DE 10 2006 037 941 describes a steering sensor with a housing (supporting part) made of metal. A bearing ring is connected with the housing by a plastic connection. Manufacturing tolerances are to be minimized overall. The production process related to the housing is quite complex. The positioning of a rotor inside the housing is not described any further.